Multi Image Upload with PHP, Ajax and vanilla Javascript

Hello Developer, i need a Multi Image Upload for a classifieds website. Here are the requirements about this project in short language:

// Filestructure
- item-new.php
- item-edit.php
- images/$item_id/...$images...

// DB Structure
-- items_images
image_id | item_id | path | name | ext | ordering | date_created

Conditions --->
- create 2 images from original -> " small " and " big " -> delete the original ( if possible, do not upload at all )
- add watermark on bottom right (image in png)
- let user sort, rotate, delete it and let him set a main image ( order_pos 1 ).
- images are generated at "form-send" action ( item new or item edit page ).

- Only pure PHP, vanilla Javascript, Ajax
- No dependencies to other Frameworks/Stylesheets/JQuery
- Must fit to all mayor Browsers -> Chrome , Safari , Edge , Firefox , Samsung , Opera

- User interactions - Move l/r , Rotate l/r , delete , set as Main image
--- if possible make the "movement" of an image "draggable" to the user.

// Settings for images
$minFiles = 1 ;
$maxFiles = 20 ;
$maxSize = 5 ; // mb
$fileTypes = [ "image/jpeg", "image/png"] ; // protect from other formats
$rotation = 90 ; // degree on one click

// set only the height or the width ( calc it ) ---> don`t crop it.
$imgSmallW = 240 ; // px
$imgSmallH = 150 ; // px

$imgBigW = 1000 ; // px
$imgBigH = 600 ; // px

$watermark = url("/images/system/watermak.png") ; // add it on generate image to the bottom right corner
$watermark_w = 60 ; // px
$watermark_h = 30 ; // px

$imgQuality = 0.8 ;
$order_pos = get_pos_id ; // generate pos_id from selected sequence from user ( e.g. left to right -> 1 - 20 )

// save form procedure for item-new.php
$image_id = AUTO_INCREMENT; // will set from DB
$item_id = $_POST['id']; // is generated from website when the form is succsessfully send...
$path = "images/" . $item_id . "/";
$name = "eto-" . $item_id . "-" . $image_id;
$ext = "jpg or png";
$ordering = $order_pos;

// get form with item-edit.php
$item_id = $_GET['id']; // the id is instantly accessible when opens, please preload all images from the item

I am eagerly awaiting your offers.